PT - JOURNAL ARTICLE AU - Flemming Madsen AU - Jann Mortensen AU - Lars Bjerre-Kristensen AU - Ole Find Pedersen TI - Quality control of pneumotach's for routine spirometry. Results from a national audit DP - 2014 Sep 01 TA - European Respiratory Journal PG - P1997 VI - 44 IP - Suppl 58 4099 - http://erj.ersjournals.com/content/44/Suppl_58/P1997.short 4100 - http://erj.ersjournals.com/content/44/Suppl_58/P1997.full SO - Eur Respir J2014 Sep 01; 44 AB - IntroductionAs part of a nationwide study sampling data to establish reference values for spirometry, lung volume and lung diffusion capacity we performed an audit of the participating laboratories.We hypothesized that the quality of lung function equipment could be controlled and improved.MethodsAn on-site audit of the laboratory equipment was performed. We applied calibrations traceable to international standard and calibrated all pneumotachs with a transportable decompression flow calibrator at three flow levels, since flow is difficult to calibrate with a syringe if not motor driven. The coefficient of variation of the volumes delivered was 1%Before the calibration with the decompression flow calibrator, we conducted manual three- flow volume calibration with a 3 liter syringe.ResultsFifteen laboratories (16 pneumotachs) were audited. At all the laboratories, the manual calibrationwith the 3 liter syringe was conducted without errors.With the decompression flow calibrator at high and medium flow, the FEV1 was outside 4% of the nominal value in three pneumotach's and at low flow in four cases. The maximal deviation was 10%.Discussion and conclusionCalibration with a three liter syringe seems not to guarantee adequate performance of a pneumotach concerning flow measurement. It has been anticipated that flow could be calibrated indirectly by means of a syringe by integrating the volume to a flow. Our results show that calibration with a syringe does not guarantee correct calibration of pneumothach's and we need a feasible method to perform valid flow calibrations.